[In-vitro evaluation of morphine dependence. II. Response of the fat "fundus" to 5-HT]

The kinetic of serotoninergic receptor systems was studied in an in vitro model for opiate tolerance and dependence. The fundus strip of rats chronically treated with morphine and sacrificed at different time intervals and in different conditions (with and without abstinence signs) was used. The differences between the response to the 5-HT in a situation of abstinence as compared to the same preparation in a situation of non-abstinence (in vitro model for dependence) are not statistically significant. The variations in the response as related to duration of treatment in vivo of the various groups of animals, cannot be significantly correlated to morphine-induced tolerance.